set_item_spacing

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, and the description discloses almost nothing beyond the basic mutation. It does not mention what happens if the frame is not auto-layout, whether existing spacing is overwritten, or any edge cases. The schema carries the caveats, but the description itself offers no behavioral insight.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, front-loaded sentence that gets straight to the point with no wasted words. However, it is so terse that it omits useful details that could have been included without bloat.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple setter with a well-documented schema, the description is mostly adequate. Yet it lacks any mention of prerequisites, failure modes, or behavior when constraints are violated, leaving some gaps for a mutation tool with no output schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, and the schema already explains each parameter thoroughly, including the SPACE_BETWEEN and WRAP caveats. The description adds no meaning beyond what the schema provides, so the baseline score of 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly identifies the action ('set'), the resource ('item spacing'), and the specific context ('children in an auto-layout frame'). This distinguishes it from sibling tools like set_padding or set_layout_mode, which target different properties.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides clear context by limiting the tool to auto-layout frames, but it does not explicitly state when not to use it or mention alternatives. The context is implied rather than fully spelled out.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.